The loss of sea ice in the Arctic will allow ships to navigate freely across the North Pole by the middle of the century and could lead to unprecedented geopolitical tensions between countries that have territorial claims in the region, scientists said.

Ice-breaking ships that are only moderately strengthened against sea ice will be able to cross the Arctic Ocean with impunity during the late summer months starting from about 2050, the scientists found in a study of how the loss of the floating sea ice will affect commercial shipping.

New routes will open up between the Atlantic and Pacific Oceans which will allow shipping companies to abandon traditional courses through the Panama and Suez canals. Instead, they will be able to sail unhindered over the top of the world for much of the summer, the scientists found.

However, long-standing tensions between the Arctic nations, even between traditional allies such as Canada and the US , will surface as nations vie for political and economic control of the new shipping lanes, said Laurance Smith, professor of geography at the University of California at Los Angeles .

“The development is both exciting from an economic development point of view and worrisome in terms of safety, both for the Arctic environment and for the ships themselves,” said Professor Smith, co-author of the study published in the journal Proceedings of the National Academy of Sciences.

The sea ice of the Arctic during the summer months has melted by about 25 percent on average in terms of surface area over the past 30 years. Scientists believe this is down to climate change caused by rising levels of carbon dioxide in the atmosphere.

Last September, the month of the minimum sea-ice extent, set a new record. Scientists estimated that sea ice covered 1.32 million square miles, which was nearly 300,000 square miles – an additional area of open ocean greater than the state of Texas – less than the previous record minimum set in September 2007.

Arctic experts believe that a totally ice-free summer Arctic could occur as early as 2030, with some suggesting it could happen within the next five to ten years. Almost all computer models predict an ice-free summer in the Arctic Ocean by the end of this century.

The latest study found that even under moderate climate-change scenarios, where rises in carbon dioxide do not follow the highest-possible course, could still lead to new Arctic shipping lanes opening by the around the middle of the century.

“We're talking about a future in which open-water vessels will, at least during some years, be able to navigate unescorted through the Arctic , which at the moment is inconceivable,” said the study's co-author, Scott Stephenson of UCLA.

Polar icebreakers will soon be able to cross directly over the North Pole rather than traversing the Northwest Passage around the coast of Canada and Alaska , or the Northern Sea Route along the coastline of Russia . “Nobody's ever talked about shipping over the top of the North Pole. This is an entirely unexpected possibility,” Stephenson said.

“No matter which carbon emissions scenario is considered, by mid-century we will have passed a crucial tipping point – sufficiently thin ice – enabling moderately capable icebreakers to go where they please,” he said.

At the moment, the Northwest Passage is navigable in summer only about once in every seven years, making it too unreliable for commercial shipping. But in 40 years' time, it should be accessible every year, creating commercial tensions between Canada and the US given that Canada claims that the passage falls under its sovereignty whilst the US insists it is an international shipping route.

Meanwhile, Russia could lose out to its lucrative trade in escort fees from vessels navigating the Northern Sea Route , the scientists said. The disappearance of the sea ice could mean that ships take the shorter route over the North Pole, outside the jurisdiction of the 200-mile exclusive economic zone off the coast of Russia – although Russia has made territorial claims extending out to the North Pole.

Citing the study Climate Central's Andrew Freedman [2] reported:

Laurence C. Smith, the study's lead author, said that even a moderate amount of warming will open the Arctic up to a degree that would have been unthinkable to prior generations of polar explorers, many of whom died trying to find viable sea routes across the Arctic .

For example, the study found that the Northern Sea Route along the Russian Coast , which is already used by ice-strengthened ships to transport goods between Europe , Russia , and China , is likely to become even more accessible, including to non-ice-hardened vessels, the study found.

According to the study, during the 1979-2005 period, sea ice limited the probability of an open-water transit along the Northern Sea Route to just 15 percent in any given year. The study projects those odds will increase to 94 to 98 percent by 2040-2059, depending on how much the Arctic warms during the period.

Meanwhile, ships that have been modified to withstand encounters with some ice floes may be able to sail straight across the pole, bypassing Russian waters and thereby saving time and money, since Russia currently charges hefty icebreaker escort fees for vessels traversing its Arctic waters.

Currently, only icebreakers are regularly able to make voyages across the Pole. Last summer, the Chinese icebreaker Xuelong, or Snow Dragon, traversed the Northeast Passage , along the coast of Siberia , and then took a shortcut over the North Pole to travel back to China .

If sea ice recedes and thins to a point where icebreakers are no longer necessary to reliably navigate this path, the Central Arctic Shipping Route that could shave up to 8,000 miles off the journey from Shanghai to Europe , slashing transport costs.

The new study also projects that access to the famed Northwest Passage will become more reliable to ice-hardened vessels. The Northwest Passage will likely be most attractive for trans-Arctic shipping to and from eastern North America , the study said.

The results don't necessarily indicate that the Arctic is going to be quickly overrun with shipping and resource development, as some have argued. But they do suggest that as the Arctic continues to warm in response to human activities, people will have unprecedented access to the previously frozen and isolated region.

In 2012, September sea ice extent plummeted to its lowest level since the beginning of satellite records in 1979. The past six years have had the six smallest sea ice extents since 1979, indicating that the ice has not recovered from the previous record low in 2007.

Smith said that whether shipping companies choose to take advantage of shorter Arctic routes during the end of the melt season will depend on a range of factors beyond just sea ice conditions. “It takes more than technical feasibility to make shipping happen,” he said.

A 2009 assessment of Arctic maritime shipping found that the Arctic lacks basic services that are necessary for safe shipping operations, including reliable navigation charts. "A lack of major ports, except for those in northern Norway and northwest Russia , and other critical infrastructure will be significant limitations for future Arctic marine operations," the report said.

Along similar lines, sailing along a supra-polar route might cut the shipping distance involved, but the lack of nearby ports and search and rescue capabilities in the middle of the Arctic Ocean would make the trip far riskier than the routes currently in use today. That would increase liability costs for shippers.

For these reasons and more, Smith does not expect the Arctic to ever replace the Suez and Panama canals, which are the main arteries for global marine transport today. However, a seasonally ice-free Arctic could boost the ability of companies to transport natural resources and goods from northern Europe and Russia to China .

“This is highly significant because it provides a shipping corridor to get those resources to China ,” Smith said.

Smith said the study clearly shows the need for an effective governance system to oversee Arctic shipping and set standards to prevent accidents that could damage the fragile ecosystems in the region. “The ice is thinning to the point where it is feasible” for ships to go anywhere, Smith said. “Even the temptation of it in my mind is worrisome because of the sheer numbers of ships that it involves.”

The International Maritime Organization has devised a voluntary safety code for Arctic-going vessels, but Smith said mandatory standards may be needed.